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所在平台: Udemy |
课程主页: https://www.udemy.com/course/polymers-q/
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**课程名称：** 聚合物：人类的财富 **课程概述：** 本课程将深入探讨聚合物的奥秘，包括其在自然界和人类社会中的重要作用。我们将从以下几个方面展开： * **天然聚合物：** 了解存在于动植物中的天然聚合物，如橡胶、蛋白质、纤维素、淀粉（多糖）、木材、丝绸和核酸。 * **合成聚合物：** 认识人类在实验室和工厂中创造的合成聚合物，例如聚乙烯、PVC、尼龙、涤纶、特氟龙、合成橡胶、酚醛树脂和三聚氰胺。 * **半合成聚合物：** 探索通过化学手段改性天然聚合物而得到的半合成聚合物，如硝化纤维素和醋酸纤维素。 * **聚合物结构与性质：** 学习聚合物的结构如何影响其物理性质。我们将区分： * **线性聚合物：** 单体连接成长的直链，具有高密度、高拉伸强度和高熔点，例如高密度聚乙烯 (HDPE)。 * **支链聚合物：** 线性链上带有侧链，结构不规则，因此具有较低的拉伸强度、较低的熔点和较低的密度，例如低密度聚乙烯 (LDPE)。 **课程目标：** 通过本课程的学习，您将能够： * 区分不同类型的聚合物（天然、合成、半合成）。 * 理解常见的聚合物在日常生活中的应用。 * 解释聚合物的结构（线性或支链）如何决定其关键物理性质。 **教学大纲：** （本课程没有提供详细的教学大纲。）
Natural polymers: The polymers which occur in nature i.e., which occur either in plants or animals, are called natural polymers. For example, natural rubber, proteins, cellulose, starch (polysaccharides), wood, silk and nucleic acids are natural polymers.Synthetic polymers: Synthetic polymers are man-made polymers. Thesepolymers are made in laboratories or factories. Typical examples of synthetic polymers include polyethene, PVC, nylon, terylene, Teflon, synthetic rubber, Bakelite and melamine.Semi-synthetic polymers: Chemically modified natural polymers are called semi-synthetic polymers. For example, nitrocellulose, cellulose acetate etc. are termed semi-synthetic polymers. These polymers are also called chemically modified natural polymers.Linear chain polymers: The polymers m which the constituent monomers link with each other to form a long straight chain are called linear chain polymers, or straight chain polymers.Linear polymers are well packed and thus have high densities, high tensile strength and high melting points. For example, high-density polythene (HDPE) is a linear chain polymer.Branched chain polymers: The Polymers which have side-chains attached to the linear chains consisting of monomers are called branched chain polymers.The branched chain polymers are irregularly packed and thus have lower tensile strength, lower melting point and lower density. For example, low-density polythene (LDPE) has lower density, lower melting point and lower tensile strength than the linear high-density polythene (HDPE).
